The present invention relates generally to devices for use in the testing and burn-in of integrated circuits (IC's) and particularly to devices for the testing and burn-in of IC's that are intended for use in multichip modules (MCMs).
When ICs are packaged into MCMs it is important to have a high level of confidence that the ICs will meet the electrical requirements and survive an infant morality test or "burn-in" before assembling them into MCMs. A quality level in excess of 99 percent for individual ICs is desirable.
Typically, ICs must be assembled into a package before conducting full electrical tests and burn-in. If the IC is to be packaged into an MCM, it must then be removed from the package and re-assembled into the MCM. This removal and repackaging process can cause damage to the die and is not practical for high pin count ICs.
In the past, various methods for testing and burning in individual die have been used. Tape Automated Bonding (TAB) has been used to attach the die to a leadframe which fans out the bonding pads and can be mounted in a test fixture. Sacrificial packaging has been used therein the die is mounted and wire bonded into a single chip package, and then removed after testing and burning in. A third approach has been to bond the die to a fanout substrate by wire bonding or flip chip solder reflow, and then excise the substrate or break the solder bonds after the test and burn in procedure. The past methods all require metallurgical connections to the pads of the bare die and thus have the problems associated with the removal of these connections.
Thus a need exists for a carrier or fixture that will serve as a temporary package for a single as processed IC or bare die and provide an electrical and mechanical interface to test and burn in equipment. The need is for a fixture that makes electrical connections between all of the bonding pads on the die and the corresponding external connectors and also permits easy insertion and removal of the die without physically damaging it in any way.